阅读说明：本技术 一种数控车床去除工件螺纹起始段飞边或毛刺的方法 (Method for removing burrs or burrs at starting section of workpiece thread by numerical control lathe ) 是由 刘建群 孙凤芝 刘珈利 何永玲 黎泉 石南辉 贾广攀 于 2019-10-09 设计创作，主要内容包括：本发明提供一种数控车床去除工件螺纹起始段飞边或毛刺的方法,包括以下步骤：在工件上车削螺纹后,将车刀返回至螺纹的最后切削行程起点；设置车刀对飞边或毛刺的切除量；按所述螺纹原有的切削参数作螺纹插补,车削螺纹并定位车刀至螺纹的实际起点；沿所述螺纹起始段倒角走向,以锐边螺旋最大导程作等导程螺纹插补,进行对飞边或毛刺的车削。该数控车床去除工件螺纹起始段飞边或毛刺的方法能够精准切除飞边或毛刺的根基,且无需更换刀具,省去更换刀具的麻烦。(The invention provides a method for removing burrs or burrs at the starting section of a workpiece thread by a numerical control lathe, which comprises the following steps: after the thread is turned on the workpiece, returning the turning tool to the starting point of the final cutting stroke of the thread; setting the cutting amount of the turning tool to the flash or burr; performing thread interpolation according to the original cutting parameters of the thread, turning the thread and positioning a turning tool to the actual starting point of the thread; and (3) performing equal-lead thread interpolation by using the maximum sharp-edge spiral lead along the chamfer trend of the starting section of the thread, and turning the flash or the burr. The method for removing the burrs or burrs at the starting section of the threads of the workpiece by the numerical control lathe can accurately remove the roots of the burrs or burrs without replacing a cutter, so that the trouble of replacing the cutter is avoided.)

1. A method for removing burrs or burrs at the starting section of a thread of a workpiece by a numerical control lathe is characterized by comprising the following steps:

after the thread is cut on the workpiece, the turning tool is returned to the starting point S [ X ] of the final cutting stroke of the thread_S,Z_S]Wherein X is_SIs the radial coordinate of the starting point S of the final cutting stroke, Z_SIs the axial coordinate of the starting point S of the final cutting stroke;

setting the cutting amount r of the turning tool to the flash or burr;

performing thread interpolation according to the original cutting parameters of the thread, turning the thread and positioning a turning tool to the actual starting point of the thread: turning the thread to the actual starting point A [ X ] according to the lead P of the thread_A,Z_A]Wherein Z is_AIs the axial coordinate of point A, Z_A＝[h-hc]*sin[c]*cos[t]/sin[90-t-c]Wherein h is the thread profile height of the thread, t is the taper half angle of the thread, c is the chamfer angle of the thread, hc is the radial height of the chamfer of the starting end of the thread, X_AIs the radial coordinate of point A, X_A＝[Z_S-Z_A]*tan[t]*2+X_S；

Along the starting section chamfer trend of screw thread, make equal lead screw interpolation with sharp edged spiral maximum lead, carry out the turning to overlap or burr: controlling the turning tool from the position A [ X ] according to the maximum lead Pc of the sharp-edge spiral and the chamfer angle c of the thread_A,Z_A]Thread turning to point B [ X ]_B,Z_B]And finishing the turning of the flash or burr, wherein Pc-P-sin [90-t-c ]]*sin[s]/sin[s+c]/cos[t]Wherein s is the thread profile half angle of the thread, Z_BIs the axial coordinate of point B, Z_B＝-hc*tan[c]+Z_A；X_BIs the radial coordinate of point B, X_B＝hc*2+X_A。

2. The method for removing the flash or burr of the thread start section of the workpiece on the numerically controlled lathe as recited in claim 1, wherein the point of the origin of the coordinate system is selected to be the center of rotation of the lathe on which the thread start section is located.

3. The method for removing the flash or burr of the thread start section of the workpiece by the numerically controlled lathe according to claim 1, wherein the cutting amount r is 0.1 mm.

4. The method for removing the flash or burr of the thread start section of the workpiece by the numerically controlled lathe according to claim 1, wherein the workpiece is a petroleum pipe.

5. The method for removing the flash or the burr of the thread starting section of the workpiece by the numerically controlled lathe as claimed in claim 1, wherein the step of setting the cutting amount r of the lathe tool to the flash or the burr comprises the following specific steps: and axially moving the turning tool for a distance r along the position facing the flash or burr.

Technical Field

The invention relates to the technical field of numerical control machining of threads, in particular to a method for removing burrs or burrs at the starting section of threads of a workpiece by a numerical control lathe.

Background

The oil pipe thread specification stipulates that the small end (the initial end) of the thread should be chamfered at 60 degrees or 65 degrees, after the turning processing of a forming cutter is completed, burrs or burrs are generated on an incomplete section in a lead range of about 0-1.5 times of the initial chamfer section of the thread, and the burrs or the burrs are positioned on the far end face side (the near end face side of a thread groove) of a thread profile. The existence of the flash or the burr not only influences the normal detection of thread parameters, but also influences the sealing performance of the thread in use, increases the risk of damage to the surface of the thread, and even leads to the failure of threaded connection.

The existing method for removing the flash or burr is to replace a cutter after the thread turning is finished, repeatedly chamfer by using a sharp wide-edge turning tool and (or) manually polish by using a file. The manual grinding with the file has the disadvantages of low efficiency, manual participation, increased risk of accidental damage to the surface of the thread and additional labor cost investment. In addition, after the tool is replaced, the tool needs to be mounted and corrected again, which also reduces the thread machining efficiency. For example, chinese patent application publication No. CN104084653A discloses a thread burr removing method that requires the exchange of a wide edge when removing burrs.

At present, the existing rules of the flash or the burr are rarely researched in the prior art, and the flash root cannot be accurately cut off, so that the incomplete thread teeth attached with the flash or the burr are generally cut off gradually and decreasingly from the whole in the prior art, the cutting range is wide, the cutting amount is large, a wide cutting edge is adopted for improving the efficiency and pursuing the whole cutting effect, the cutting process needs to be cut off circularly by multiple cutters, more maneuvering time is occupied, and the cutting load is large. For example, in document 1 (huangminggi. shaving thread half teeth on a common numerical control lathe [ J ]. metal working (cold working), 2012(20):35-36) and document 2 (marjoram, royal source; development and application of shaving thread half teeth based on a numerical control lathe [ J ]. metal working (cold working), 2015(21):71-73), tools need to be replaced after thread turning, flash or burr removal is carried out by using an additional wide-edge tool, and both documents adopt a mode of shaving 1/2 turns of thread half teeth, the allowance is large, and multiple cutting is needed, and the sharp edge attached to the flash is usually only 1/2 turns. Furthermore, both documents focus on the start and end ends of a straight thread without taper, which is not suitable for flash or burr removal of tapered threads.

Disclosure of Invention

In view of the above problems, it is necessary to provide a method for removing burrs or burrs at the beginning of a thread of a workpiece by a numerically controlled lathe, which can precisely remove the roots of the burrs or burrs without replacing the tool, thereby eliminating the trouble of replacing and calibrating the tool.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a method for removing burrs or burrs at the starting section of a workpiece thread by a numerical control lathe comprises the following steps:

after the thread is cut on the workpiece, the turning tool is returned to the starting point S [ X ] of the final cutting stroke of the thread_S,Z_S]Wherein X is_SIs the radial coordinate of the starting point S of the final cutting stroke, Z_SIs the axial coordinate of the starting point S of the final cutting stroke;

setting the cutting amount r of the turning tool to the flash or burr;

performing thread interpolation according to the original cutting parameters of the thread, turning the thread and positioning a turning tool to the actual starting point of the thread: turning the thread to the actual starting point A [ X ] according to the lead P of the thread_A,Z_A]Wherein Z is_AIs the axial coordinate of point A, Z_A＝[h-hc]*sin[c]*cos[t]/sin[90-t-c]Wherein h is the thread profile height of the thread, t is the taper half angle of the thread, c is the chamfer angle of the thread, hc is the radial height of the chamfer of the starting end of the thread, X_AIs the radial coordinate of point A, X_A＝[Z_S-Z_A]*tan[t]*2+X_S；

Along the starting section chamfer trend of screw thread, make equal lead screw interpolation with sharp edged spiral maximum lead, carry out the turning to overlap or burr: helical maximum lead Pc on sharp edge, said screwThe chamfer angle c of the thread controls the turning tool from said position A [ X ]_A,Z_A]Thread turning to point B [ X ]_B,Z_B]And finishing the turning of the flash or burr, wherein Pc-P-sin [90-t-c ]]*sin[s]/sin[s+c]/cos[t]Wherein s is the thread profile half angle of the thread, Z_BIs the axial coordinate of point B, Z_B＝-hc*tan[c]+Z_A；X_BIs the radial coordinate of point B, X_B＝hc*2+X_A。

Further, the rotation center of the lathe where the thread starting end is located is selected as the origin of the coordinate system.

Further, the cutting amount r is 0.1 mm.

Further, the workpiece is a petroleum pipe.

Further, the step of setting the cutting amount r of the turning tool to the flash or burr specifically comprises: and axially moving the turning tool for a distance r along the position facing the flash or burr.

Due to the adoption of the technical scheme, the invention has the following beneficial effects:

1. the method for removing the burrs or burrs at the thread starting section of the workpiece by the numerical control lathe is based on the existence law of the burrs or burrs (namely the burrs or burrs are attached to the edge at the junction of the outer surface of the thread and the chamfer conical surface, and the edge is in a variable-lead spiral shape along the chamfer angle conical surface), and according to the existence law of the burrs or burrs at the thread starting section, the edge on the chamfer surface is chamfered according to the maximum sharp-edge spiral lead (which is smaller than the original lead of the thread), so that the root base to which the burrs or burrs are attached can be accurately and controllably cut off, and the burrs or burrs are completely removed without residues.

2. Because the method for removing the burrs or burrs at the starting section of the threads of the workpiece by the numerical control lathe can accurately remove the roots of the burrs or burrs, the method has small removal amount, does not need to change the tool, can solve the problem by using the original threading tool by a short stroke once, does not need multi-tool circular removal, saves the troubles of replacing and calibrating the tool, and can improve the precision and efficiency of thread machining; and because the material cutting amount is small, the cutting load is small.

3. According to the method for removing the burrs or burrs at the starting section of the threads of the workpiece by the numerically controlled lathe, the cutting amount of the burrs or the burr roots is adjustable, and then the cutting effect can be adjusted and controlled to meet different requirements.

4. The method for removing the flash or the burr of the thread starting section of the workpiece by the numerically controlled lathe takes the chamfer of the thread as a technical variable when the flash or the burr is removed, so that the method is not only suitable for removing the flash or the burr of the straight thread, but also suitable for removing other types of threads, such as the flash or the burr of the conical thread starting section.

Drawings

FIG. 1 is a flow chart of a method for removing burrs or burrs at a thread start section of a workpiece by a numerically controlled lathe according to a preferred embodiment of the present invention.

FIG. 2 is a schematic diagram of a method for removing burrs or burrs at a thread start section of a workpiece by a numerically controlled lathe according to a preferred embodiment of the present invention.

FIG. 3 is a schematic structural diagram of a workpiece before a thread start segment flash is removed.

FIG. 4 is a schematic structural diagram of the workpiece shown in FIG. 3 after the flash at the thread start section is removed.

Fig. 5 is a top view of fig. 3.

Fig. 6 is a top view of fig. 4.

Wherein, 100-the base of the cut flash; 101-flashing; p-lead of thread; t-taper half angle of the thread; h-thread profile height of the thread; c-chamfer angle of the thread, hc-chamfer height of the thread start; pc-sharp edge spiral maximum lead; r-amount of excision; 200-turning tool.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1 and fig. 2, a method for removing burrs or burrs at a thread start section of a workpiece by a numerically controlled lathe according to a preferred embodiment of the present invention includes the following steps:

in step S1, after the screw is cut on the workpiece, the turning tool 200 is returned to the starting point S [ X ] of the final cutting stroke of the screw_S,Z_S]Wherein X is_SIs the radial coordinate of the starting point S of the final cutting stroke, Z_SIs the axial coordinate of the starting point S of the final cutting stroke.

Referring to fig. 3, in the present embodiment, the flash formed at the beginning of the external thread of the petroleum pipe is removed by the method. Preferably, the center of rotation of the lathe where the thread start end is located is selected as the origin of the coordinate system, so as to facilitate the calculation of the coordinates of the points.

In step S2, the cutting amount r of the burr 101 or burr by the turning tool 200 is set. Specifically, the step of setting the cutting amount r of the turning tool 200 to the flash 101 or the burr includes: the turning tool 200 is moved axially a distance r towards the position of the flash 101 or burr, at which time the turning tool 200 is moved slightly to a position S' [ X ]_S,Z_S+r]. The amount of cutting r is preferably 0.1 mm. It is understood that the cutting amount r can be set to other values according to actual needs.

Step S3, performing a thread interpolation according to the original cutting parameters of the thread, turning the thread and positioning the turning tool 200 to the actual starting point of the thread: turning the thread to the actual starting point A [ X ] of the thread according to the lead P of the thread_A,Z_A]Wherein Z is_AIs the axial coordinate of point A, Z_A＝[h-hc]*sin[c]*cos[t]/sin[90-t-c]Wherein h is the thread profile height of the thread, t is the taper half angle of the thread, c is the chamfer angle of the thread, hc is the height of the chamfer of the starting end of the thread, X_AIs the radial coordinate of point A, X_A＝[Z_S-Z_A]*tan[t]*2+X_S。

Step S4, along the chamfer trend of the thread starting section, performing equal-lead thread interpolation by using the sharp-edged spiral maximum lead, and turning the burr 101 or burr: controlling the turning tool 200 from said position A [ X ] according to the sharp edge helical maximum lead Pc, the chamfer angle c of said thread_A,Z_A]Thread turning to point B [ X ]_B,Z_B]And finishing the turning of the flash 101 or the burr, wherein Pc-P sin [90-t-c ]]*sin[s]/sin[s+c]/cos[t]Wherein s is the thread profile half angle of the thread, Z_BIs the axial coordinate of point B, Z_B＝-hc*tan[c]+Z_A；X_BIs the radial coordinate of point B, X_B＝hc*2+X_A。

Researches show that the geometrical dimension of the flash 101 or the burr is related to the mechanical property of the material, the sharpness of a cutter and cutting parameters; after the thread is turned and formed, the flash 101 or the burr is attached to the edge at the junction of the outer surface of the thread and the outer surface (conical surface) of the chamfer, the edge is in a variable lead spiral shape along the chamfer angle, and the lead change range is smaller than the arc radius of the threading tool. Because the change range of the edge lead is smaller than the arc radius of the threading tool 200, on the basis, the small part of the root 100 attached to the flash 101 or the burr can be continuously cut off only by the arc-shaped tool tip of the turning tool 200 under the condition of lead change, so that excessive materials do not need to be cut off.

The method for removing the flash or the burr at the initial section of the thread of the workpiece by the numerically controlled lathe provided by the preferred embodiment of the invention uses the original tool for thread turning, takes the starting point of the final cutting stroke of the thread turning as the starting point, performs thread interpolation according to the original cutting parameters of the thread, positions the actual starting point of the thread on the conical surface of the chamfer, immediately performs equal-lead thread interpolation according to the actual trend of the chamfer (namely according to the actual angle of the chamfer) and the maximum lead of the sharp-edged spiral, keeps continuous and complete turning, and can cut off the sharp part (black part in figure 2) of the edge attached to the flash 101 or the burr, thereby achieving the effect of removing the flash 101 or the burr.

For ease of understanding, a specific example provided by an embodiment of the present invention is given below:

for the FANUC numerically controlled lathe system with the function of macro program, the last thread cutting stroke of the original program is completed and the cutting starting point S [ X ] is returned_S,Z_S]After that, the following code is added:

#501＝P；

#502＝s；

#503＝t；

#504＝h；

#505＝c；

#506＝hc；

#508＝X_S；

#509＝ZS；

M98P7777；

the following code is written to constitute a new program O7777, which can be invoked jointly by programs with different thread parameters:

O7777；

#507＝r；

#1 [ #501- #501] sin [90- #503- #505] sin [ #502]/sin [ #502+ #505]/cos [ #503 ]; (calculating the maximum helical lead with sharp edge)

#2 [ #504- #506 ]. sin [ #505] cos [ #503]/sin [90- #503- #505] - # 509; (calculating the Z-Stroke positioned to the actual starting point of the thread)

#3 ═ 2 × 2 tan [ #503 ]; (calculating X-direction travel to locate actual start of thread)

#4 ═ 506/tan [ #505 ]; (calculating and removing flash Z-direction stroke)

#5 #506 x 2; (calculating and removing flash X-direction travel)

G0W [ #507 ]; (axial offset of amount of resection Material)

G32U #3W #2F [ #501 ]; (location to starting point of flash removal along thread path)

G32U [ #5] W [ #4] F [ #1 ]; (deflashing)

G0U 20; (completion of flash removal, X-direction away from the threaded surface)

G0X [ #508] Z [ #509 ]; (Return thread cutting starting point)

M99; (Return thread turning program)

The coordinate system of the workpiece is arranged at the center of the initial end face of the thread, after the original program finishes the thread turning, the turning tool 200 is positioned at the starting point [ Xs, Zs ] of the final turning stroke of the thread, and the new program is called to remove the flash 101. For the numerical control lathe system without the macro program function, each parameter can be manually calculated and then replaced by the macro variable of the moving part of the original lathe tool. Wherein the placeholder meaning: p is a taper pipe thread lead, t is a taper half angle, s is a thread half angle, h is a thread height, c is a thread chamfer angle, hc is a thread starting end chamfer height, r is a cutting material amount axial adjustment coefficient (cutting amount), and the program input is replaced by an actual numerical value.

Referring to fig. 3 and 5 together, which are schematic structural diagrams before the deburring of the workpiece, and fig. 4 and 6 are schematic structural diagrams after the deburring is performed by using a cutting amount r of 0.1mm, it can be seen from the above-mentioned drawings that the deburring method using the above-mentioned numerically controlled lathe for removing the deburring or burring of the start section of the thread of the workpiece can completely remove the deburring attached to the sharp edge of the chamfer cone and the cutting amount is small.

According to the method for removing the burrs or burrs at the thread starting section of the workpiece by the numerically controlled lathe, the upper edge of the chamfered surface is chamfered according to the maximum sharp-edge spiral lead according to the existence rule of the burrs or the burrs at the thread starting section, the burrs or the burrs can be removed accurately, the turning stroke is fully covered, and no residue exists.

The method for removing the burrs or burrs of the thread starting section of the workpiece by the numerically controlled lathe can adapt to the change of thread parameters and structural parameters, and is not only suitable for removing the straight thread burrs 101 or burrs, but also suitable for removing other types of burrs 101 or burrs, such as tapered threads.

After the thread turning is finished, the method for removing the flash or the burr of the starting section of the thread of the workpiece by the numerical control lathe directly uses the thread turning cutter to remove the flash 101 or the burr by one stroke, and the method is continuously executed without changing the cutter.

According to the method for removing the flash or burr at the starting section of the thread of the workpiece by the numerical control lathe, the turning tool is accurately positioned, the material cutting amount is small, and the cutting load is small.

The method for removing the flash or the burr of the thread starting section of the workpiece by the numerical control lathe can set different cutting amounts, so that the cutting effect can be adjusted and controlled.

The method for removing the flash or the burr of the thread starting section of the workpiece by the numerical control lathe can remove the flash 101 or the burr on the numerical control lathe in real time without additional manpower, working procedures, tools, cutters and equipment requirements.

It is understood that in other embodiments, the cutting amount r of the turning tool 200 may be set after step S3 is executed.

It can be understood that the method for removing the flash or the burr of the thread starting section of the workpiece by the numerically controlled lathe is not limited to be used for removing the flash of the thread of the oil pipe, and the method can also be used for removing the flash of the threads of the starting sections of other workpieces.

It can be understood that the method for removing the flash or burr of the thread starting section of the workpiece by the numerically controlled lathe is also suitable for removing the burr of the thread starting section.

It can be understood that the method for removing the flash or the burr of the thread starting section of the workpiece by the numerically controlled lathe is not limited to the removal of the flash or the burr of the thread starting section of the external thread, and is also applicable to the removal of the flash or the burr of the thread starting section of the internal thread.

The above description is intended to describe in detail the preferred embodiments of the present invention, but the embodiments are not intended to limit the scope of the claims of the present invention, and all equivalent changes and modifications made within the technical spirit of the present invention should fall within the scope of the claims of the present invention.